ANN ARBOR — AT&T customers in Ann Arbor and Ypsilanti are expected to experience improved mobile Internet coverage and voice performance as a result of continued investment and innovation by AT&T.

The company announced Friday that it has completed a key initiative in its ongoing efforts to enhance the wireless capacity and performance of its mobile Internet network in Ann Arbor and Ypsilanti.

The network enhancement adds new layers of frequency, also known as “carriers,” to six cell sites, three in Ann Arbor and three in Ypsilanti, to more efficiently manage available spectrum and increase mobile broadband capacity. The expansion helps manage ever-growing demand for mobile Internet services by allocating more network resources for AT&T’s mobile Internet network.

AT&T’s mobile Internet network is based on the 3rd Generation Partnership Project family of technologies that includes GSM and UMTS, the most widely used wireless network platforms in the world. AT&T has the best international coverage of any U.S. wireless provider, providing access to voice service in more than 225 countries and data service in more than 200 countries.

AT&T also operates the nation’s largest Wi-Fi network with nearly 30,000 hotspots in the U.S. and provides access to nearly 225,000 hotspots globally through roaming agreements. Most AT&T smartphone customers get access to our entire national Wi-Fi network at no additional cost, and Wi-Fi usage doesn’t count against customers’ monthly wireless data plans.

Visitors to our local network site, http://att.com/DetroitNetwork, get a peek into AT&T’s wireless network enhancements made since January 2011. Enhancements include new cell sites, Internet speed upgrades, capacity upgrades and network connection upgrades.